Telephone system.



LE ROY W. STANTON.

TELEPHONESYSTEM. nrr ucmbk nuu NOV 211912.

Patented {0011112,

T-1 Pill! i, a

. *igwlm WHTD mas r LE ROY V7. STANTON, 0F CLEVELAND, OHIO, ASSIGNOR. OF ONEJIALF TO FRANCIS W.

DUNBAR, OF CHICAGO, ILLINOIS.

TELEPHONE SYSTEM.

- Specification of Letters Patent. Patgnted Oct, 12, 31915, 7

Application filed November 8,1912. Serial No. 730,283.

To all whom it may concern:

Be it known that 1, Ln ROY W. STANTON, a citizen of the United States, residing at Cleveland, in the county of Cuyahoga and State of Ohio, have invented certain new and useful Improvements in Telephone Systems, of which the following is a specification.

, The present invention relates generally totelephone systems and more particularly to telephone systems in which an operator receives an order and performs some actin the establishment of connections between telephone lines, whether those lines be the lines of subscribers or lines available to, or asso ciated with, operators, as in so-called trunking systems. 1

The principal objects of this invention are, first, to increase the efficiency of such systems by reducing the time required to put through connections and, second, to 1ncrease the efficiency of such systems by reducing the errors incidental to present practice. In brief, these objects are attained by providing means for indicating to a calling party when the operatoris free to receive and carry out such partys order without requiring the operator to speak to such party. In other words, a party who initiates a call waits until he receives a definite, preferably automatic, indication of the operatons attention before giving his order; the arrangement of the circuits and apparatus being such that this indication. is not perfected until the circuits between the calling party and the operator have been completed and the operator is at liberty to receive the order. This feature of my invention is capable of general application to systems employing an operator, or operators.

By way of illustration, I have disclosed my invention in connection with a. semi-automatic system such as illustrated in Figure- 1 of British Patent No. 11,290 of 1905. The invention might equally well have been disclosed in connection with other well known systems.

Other features of the invention reside in novel means for guarding the operators set against connection while in use a'nd for testing a plurality .of operators sets and connecting with the first set found to be idle.

Still other features and advantages 0 may. invention will be apparent from the fol owing detailed description taken in connection. with the accompanying drawing, and the scope of the invention will be pointed out in the appended claims. 4

The drawing is a diagram of a semi-automatic system embodying the invention and employing both manual and automatic switches; the same, as before indicated, illustrating the application of my invention to the particular system illustrated in Fig. 1 of the aforesaid British-patent.

Throughout this drawing, like characters refer to like parts.

In the system illustrated, each subscribers line is provided with an automatic switch which has access to a plurality of link-circuits which terminate in plugs adapted for connection to other telephone lines.

The diagram illustrates one subscribers substation and telephone line, one switch as sociated with said line, the multiple bank contacts of a second switch, one link-circuit in full, a second link-circuit with parts omitted, and a plurality oflines to which the link-circuits may be connected by means of manual switches, consisting in the present instance of plugs and jacks. It is, of course, to be understood that in practice, a-plurality of subscribers lines will be' employed in connection with a plurality of link-circuits and that the latter will be arranged for connection with any one of a numberof other telephone lines, which may be either subscribers lines such as that illustrated, party lines such as shown in the aforesaid British patent, trunk lines, or any other desired circuits.

Referring to the drawing in detail, A des-- ignates "a substantion connected by a telephone line L with the exchange where switch M, individual to the line, is arranged to extend its circuit to link-circuits, such as N, which terminate in plugs arranged for connection with the jacks of other telephone lines L and L At" the substation, l0 designates a transmitter which is included with an impedance coil 11' in a normally open bridge of the limbs 12 and :13 of line L. A call bell l4 and a condenser 15 are in a normally closed bridge of .these same line limbs. When the particularly and that through the transmitter 10is closed. The closing of the latter brings the --condenser l5 and receiver 16 into shunt with the impedance coil 11. .This substation cii cuit'is well knownand s merleyi illustrativie.

Other substation circuits might equally well be employed. I

The line circuit includes the line relay 18, cut-off relay 19, control. relay 20, and

their associated contacts and connections.

Line limb 12 is normally connected to ground through back contact 21 of relay 19,

and line limb 13 is similarly connected by' back contact 22 with winding 23 of line relay 18 to the live pole of battery B. A second winding 24 of relay 18 is adapted to be included in circuit through front contact 25 with an interrupter 26, and any fitting source of current such as battery 26. It is by this circuit that an inductive disturbance is placed upon the calling line as part of the signaling arrangement for indicating to the calling party when the operator is ready to receive his order. Conductors 27 and 28 connect with conductors 29 and 30 to extend the line limbs 12 and 13 to the switch M, conductors 27 and 29 continuing line limb 12 through back contact 3101 relay 20, and conductors 28 and 30 continuing line limb 13 through back contact 32 of the same relay. Contacts 33 and 34 of relay 20 and contacts35 and 36 of' line relay 18 cotiperate in the control of the switch M.

The switch M, as diagrammatically shown, includes the line wipers 37 and 38 and a private or test Wiper 39. These wipers 006perate, respectively, with bank contacts 40, 41 and 42. In operation, these wipers move from the position illustrated, over these contacts to the left in response to energizations of the motor magnet 43 which operates its.

armature 44 to cause its spring pressed driving pawl 44 to engage the ratchet teeth 45 to give the switch successive steps. The armature 44 is returned to normal by a spring 444', and the pawl 44 being yieldingly pivoted, slips by the teeth on each re turn stroke. A lazy arm 46, actuated by an insulating projection 47 carried by the armature 44, automatically makes and breaks the circuit of the motor magnet 43. A re taining pawl 48 engages the teeth 45 to retain the switch in the positions to which it is advanced by the magnet 43. A spring 49 acts upon the retaining pawl 48 to hold it in engaging positions, but allows it to be removed therefrom by the spring catch 50 having a hooked end adapted to engage a hooked. projection 51 upon the said retaining pawl to lift it out of engagement inresponse to the'return stroke of armature ol the release magnet 53. A spring 54 normally tends to hold the armature in its retracted positions hen the retaining pawl 48 is withdrawn, a sprin 55, coiled 'about the shank of the movable leme t of the switch and acting against an abut cut 56, restores the switch to its normal position. Upon such restoration, the insulating projection. 57 upon the lateral arm 58 moves the spring catch out of engagement with the retaining pawl 48 and allows it to return to operative relation with the teeth 45. Normally-open contacts 59 and 60are arranged in the path of movement of the insulating projection 61 upon the movable element of the switch so as to be moved into engagement by such projection when the switch has overrun its operative contacts. This, aswill appear hereinafter more fully, brings about a release of the switch. A protective resistance 61 is included between the live pole of the battery B and the contact 60.

Such second, or

-switches are to be associated to provide a plurality of link-circuits available to any one of a plurality of telephone lines.

The link-circuits, to which the switch M and all other similar switches of the same group have access, comprise, respectively, a tip strand 65, a sleeve strand 66 and an additional control strand 67. In the diagram, a

plurality of such sets of strands are indicated. One is shown in full and is that one encountered upon the first step from normal of the switch shown in fulL- Another is shown in part and is that engaged upon the fifth step of the same switch. Others are indicated by the multiple strand connections to contacts 40, 62 in the case of the tip strand, contacts 41, 63 in the case of the sleeve strand, and contacts 42, 64 in the case of the control strand. These latter corre spond to each of the other steps of the switch shown in full. As here shown, the linkcircuits of the first four encountered con tacts have one operators transmitter 68 and receiver 69 and one control relay 70 common to them, while the second four have a second operators receiver and transmitter and a second relay 70 common to them.

The illustration is, of course, not limited to twooperators positions, nor to a definite number of cords for 'any position. Each dink-circuit N includes asleeve relay 71 and a tip relay 72 associated with the switch end of the link-circuit and a sleeve-relay 73 and tip relay 74 associated with the opposite, or connecting, end of the link-circuit. These relays possess a plurality ofnfun'ctions. They control the supervisory lamps 7 5 and 76. This control is exercised through the contacts 77 and 78 of relays 71 and 72 for lamp 75 and through the contacts 79 and 80 of relays 73 and 74 for lamp 76. Pilot re- 81 and 82, common to a group of linkcircuits, control, by contacts 85 "antl 86 respectively, corresponding pilot lamps 83 and 84. The control relay 70 is common to a group of link-circuits and is controlled by means of a plurality of series of relay contacts, one series of such contacts being provided ineach link-circuit of the group. It's circuit can only be closed through the simultaneous closure of a series of contacts including contact 87 of a relay 73, contact 88 of a relay 71, and contact 89 of a relay 72. Each link-circuit controls a call lamp 90. Its circuit extends through a front contact 91 of relay 72, aback contact 92 of relay 73 v and a front contact 93 of relay 71. The switch release circuit of each link-circuit is closed from battery B through common relay 82, contact 93 of relay 71, contact 92 of relay 73 back contact 91 of relay 72, conductor 67 back contact 36 of relay 18 and release magnet 53 to ground. The oprators receiver, 69, is included in circuit with the secondary winding of the induction coil 94 and with the condenser 95. The two common sides of this circuit extend through back contacts, 96 and 97 of each relay 73, front contacts 98 and 99 of each relay 71.

and front contacts 100 and 101 of each relay 72, comprehended in each of the link-circuits with; or other certain well known circuit arrangements may be employed. Test relay 107 is common to the same link-circuits as the operators set with which it is associated. As illustrated, it is controlled through the back contacts of the sleeve relavs7 3 of the associated link-circuits, while the relays 74 are controlled through front contacts 108.

As illustrated, the armature 106 of the test relay 107 is attracted and causes a momentary disturbance, or click, in the operators circuit, when a busy line is tested, Each control relay 70, when energiz'ed, connects the conductors 67 of all the link-circuits to which the said relay 70 is common, directly to ground through a protective resistance 109. This oonne tion is brought aboutby armature contact 10 and individual contacts 111, 112, 113,114 etc.,

one such contact being provided :for e ch link-circuit of a group. In other wor s,

' one such contact will be provided for each link-circuit common to the relay 70. Ring are capable of use.

ing key ll5 ll6,when operated, breaks the strands and 66 and brings the ringing generator 117 and the impedance coil 118 into circuit. Similarly, ringing key 119 120 brings ringing generator 121 into circult.

The telephone lines L and L asbefore indicated, may be subscribers lines similar to the line] L upon whichthere is a single substation, or a subscribersline having a plurality of substations, such as "shown in the aforesaid British patent. 0r again, the telephone lines L andL may be 'trunk. lines extending to a distant exchange, or exchanges, or to another part, or other parts,

'ofthe same exchange. Or they may be other circuits with which the link-circuits The lines L and L are provided with multiple jacks 122 and 123 available .to the different groups of link circuits N These jacks are provided for the reception of the plugs P of such circuits.

Similar multiple jacks 124 are provided for the subscribers line L, their tip and sleeve contacts being connected, respectively, to extension conductors 27 and 28.

In the operation of the system, if it be assumed that a party at substation A desires to converse with a party having a station on line L, or upon aline reached by way of line L, then, uponremoving his receiver 16 from its switch-hook 17, a circuit will be completed through the line relay 18, through winding 23 of said relay, the back contacts 21 and 22, the line limbs 12 and 13, and the bridge through transmitter 10 and induction coil 11. 'The resulting energization of line relay 18 immediately closes the circuit of interrupter 26 and, by reason of the transformer action of the windings 23 and 24 of relay 18, current is induced upon the line Y L such as to produce a noise or buzz in the receiver 16. In this form of the invention, this buzzing noise continues until the selected operator is ready to receive the order of the calling party. Being instructed as to this operation of,the system, the calling party awaits the discontinuance of this noise before entering his order. The energization of line relay 18 also closes a circuit for control relay 20 which may be traced from battery, through the winding of said' relay, front contact 36, wiper 39, to ground at125. The resulting energization of relay 20 opens contacts 31 and 32, thereby disconn'ecting wipers 37 and 38, during their advance movement so as to prevent interference with conversations over multiply connected circuits. The energization of relays 18'and 20 also closes a circuit for motor magnet 43 which may be traced from the live pole of the battery, through the winding of said magnet 43, lazy arm contact 46 and frontqcontacts 35 and 33 to ground at 126. Upon the first energization of magnet 43,

I operator.

the completion of the operatorswuciut, in-

vances as long as such grounded condition is encountered, the circuit of relay 20 being maintained and the motor magnet 43 advancing the switch step by step. When, however, a link-circuit is found which is not guarded by such a ground, of. either nature, then strand 67 is open and there being no connection for relay 20 extending to ground through the wiper 39 is deenergized and the switch stops with its wipers in engagement with the strands 65 and 66 of the selected link-circuit. The closure-of con= tacts 31 and 32 unites the extension conductors 2728 and. 2930. As soon as this takes place, a circuit is completed through sleeve supervisory relay 71 and cut-ofi relay 19. This circuit. may be traced from battery, through the winding of relay 71, strand 66,

contact i1, wiper 38, conductor 30, back contact 32, conductor 28 and winding of cut-oil relay 19 to ground. As a result, relay 19 interrupts the circuit through the line relay 18 and thereby removes the special signal from the calling partys circuit and therefore indicates to him that the apparatus is in condition for him to give his order to the This occurs sinuiltaneously with cluding the transmitter 68 and the receiver 69. The operator is thus free to receive the order. Theclosing of the front contacts 21 and 22 of relay 19 extends the circuit of the line limbs 12 and 13 through to the linkcircuit strands 65 and 66. The closing of front contact 22 also provides a path for the flow of current in shunt with the cut-off relay 19, out over line limb 13, through the substation and back through line limb 12, through the extension conductors 27 and 29 to tip strand (55 of the link-circuit, and thence to ground through tip supervisory relay 72. The closing of this circuit energizes relay 72 which results in the lighting of pilot lamp 8% and in lighting of the call lamp 90 which is individual to the particular link-circuit selected.

It may be pointed out here that the ad just-ments of relays 18 and 71 and are such as to render said relays sluggish so that tip relay 72 will have time to be actuated to open its haclc'contact 91 before the release magnet cah be operated, in case the release circuit should be momentarily closed, the circuit, as before traced, extending from greases the live pole of battery B, through relay 82, front contact 93 of relay 71, back contact 92 of relay 73, back contact 9173f relay 72, conductor 67, switch contac 42, wiper 39, back contact 36 of relay 18, and the winding of release magnet 53 to ground.

The lighting of lamps 84 and 90 is brought about upon the energization of relays 71 and 72. A circuit then extends from the live pole of battery B, through the winding of relay 82, front contact 93 of re-- lay 71, back contact 92 of relay 73, front contact 91 of relay 72, and the lamp 99 to ground. This circuit lights the lamp 90 and energizes relay 82 to close its front contact 86 to complete a circuit from battery, through pilot lamp 8% to ground. The lighting of the lamp 90 indicates to the operator which link-circuit N the call is coming in on and indicates to her which plug P to pickup for readiness in extending the call. The energization of relays 71 and 72 also closes a circuit for control relay of the group of link circuits which includes the one selected. This circuit extends from the livepole of Batteryld, through the winding of relay 70, back contact 87 of relay 73, front contact 88 of relay 71, and front contact 89 of relay 72, to ground. The energization of relay70, as aresult of the 010s ing of this circuit, closes its contact 110 upon contacts 111, 112, 113, 11 1-, etc, and thereby places a ground connection directly upon the conductor 67 of the several linkcircuits of the group. As before pointed out, the switches will not stop in connection with link'circuits upon which this ground connection exists. The energization of relays 71 and 72 also connects the operators .set, including transmitter 68 and receiver 69, into circuit with the strands 65 and 66, the receiver being placed directly in bridge of these strands. be traced from strand 65, through front contact 101' of relay 72, front contacts 98 of relay 71, back contact 97 of relay 73, the secondary winding of induction coil 9 1, receiver 69, condenser 95, back contact 96 of relay 73, front contact 99 of relay 71, front contact 100 of relay 72, to strand 66. The primary portion of this circuit extends from the live pole of battery B, through the pri mary winding induction coil 94, transmitter 98, and thence through impedance coil 10 i, and condenser 105 in parallel therewith, to ground. Because the euergiration of relays 71and 72 and the deenergization of relay 73 are required to connect the operators set into circuit and because this condition is required to cause the operation of re ay 70 to momentarily guard any of the link-circuits to which the operators set is common from selection, it will be seen that the switches M will not stop in engagement with link-circuit N unless the operators' set com- This bridge circuit may- 1,1caaae I mon to such link-circuits is free and the operator ready to recelve an order from the calling party. When such connecting condition ,does occur, the characteristic noise or distinctive signal in the callingpartys receiver is removed as a result of the deenergization of line relay 18, as before explained. As soon as the calling party observes the discontinuance of this characteristic sound, he will know that he is to give his order to the operator. The conversa-.

tional circuit between the calling party and the operator includes the heavy line conduc- I tore to the left of condensers 102 and 103,

. ing the busy test, the operator touches the tip-of her plug P against the sleeve contact of jack 122 of the line with which connection is desired. In case the line is in use, there will be an electrical potential upon such sleeve contact which will produce acurrent flow from the tip of the plug, through the sleeve strand 65, back contact 108 of relay 73, the winding of relay 107, to ground. This flow of current will energize relay 107 to close its contact 106 and produce a momentary short circuit of the branches through coil, 104 and condenser 105. The result will be a click in the receiver 69 of the operator as an indication to her that the line is in use. Upon'finding it in this condition, she will advise the calling party automatically, or by other well knownmeans, that the called subscriber is unavailable. The calling party will then restore his receiver 16 and bring about a release in the manner hereinafter explained. In case the line is found idle,the operator will insert the plug P into the jack 122 of'the line L, it being assumed that that is the line desired. Assuming that link-circuit N has direct access to line L and that such line is similar to line L, then it will be seen that as'soon as plug P is inserted. into jack 122, a circuit will be completed through sleeve supervisory relay 73 which may be traced from the live pole of battery B, through the winding of relay 73, sleeve strand 66, sleeve contacts of the plug and jack, extension conductor 28 and the winding ofcut-ofl relay' 19 of the called line to ground. The closing this circuit will energize relays 19 and 73. The former will thereupon extend the circuit to the called substation, or sub stations, and cut 0d the line relay associated with that line. The latter will interrupt the circuit of control relay 70 atback contact 87 and thereby deenergize it so that in case there be another awaiting call, it will be immediately established, or if there be no such awaiting call', the apparatus and circuits will be available and ready to receive it when it comes. The energization of relay 73 will also interrupt the circuit of pilot relay 82 and call lamp 90. As a result both lamps 84 and 90 will be extinguished. The energization of this relay 73 will also interrupt the connection between the operators receiver 69 and the'strands of this particular link-circuit, such disconnection occurring at back contacts 96 and 97. By

the actuation of its contact 108, relay 73 will also open the circuit of test relay 107 and connect tip supervisory relay 741 to tip strand 65. At the instant of inserting plug P into jack 122, the operator will depress one or other of the ringing keys to apply properringing current to ring the bell of .the wanted party. But of course, ifthere are no party lines, the operator would depress but the usual ringing key, As a result, the call-bell at the desired substation will be rung and, upon the response of the called party, a circuit will be completed for tip supervisory relay 74. The ringingcircuit. resulting from the depression of ringing key 11511-6, would extend from the live pole of the ringing generator 117, through alternate contact 115, strand 65, plug and jack tip contacts, the tip side of the circuit of the called line, through the bell at the substation and back over the sleeve side of the line, to ground through its cut-off relay, or, alternatively, through the plug and jack sleeve contacts, strand 66, alternate contact 116, c'oil 118 and battery B to ground. At this time by reason of the connection of battery B through the coil 118 to the sleeveside of the circuit, the cutoff relay associated with line L is maintainedenergized. In. case ringing key 119120 is depressed, the live pole of ringing generator 121 is connected to the sleeve side of thecircuit and ground is connected to the tip side. Otherwise the ringing circuit is the same as above described. In the latter case, however, the current from the generator- 121 relied upon to maintain the cut-oil relaybf the line L energized during, the ringing operation. Upon the response of the called party, a bridge is completed at his substation for the flow of battery current through his induction coil 11 and transmitter 10 From the sleeve side to the tip side of the circuit and thence through the tip contacts of the jack and plug, strand 65, front contact 108 of relay 73, and the winding of tip supervisory relay 74 to ground. The closing of this latter circuit opens contact 80 of 81 to ground.

this latter relay. Conversation may now be carried on between the calling and the called parties over the heavily marked conductors. it will be observed that as soon as sleeve su 'iervisory relay 73 is energized, the opcratofis set is freed for use with other link-circuits of the group and at the same time the guarding connection upon all the link-circuits of the group, resulting from the energization oi relay 70, is removed. Thus it is possible to obtain connection with a link-circuit of a particular group only when the operator's set is free and therefore only when the operator is ready to receive an order .irom the calling party.

At the conclusion of conversation, the parties restore their receivers to their switch-hooks and, as a result, the tip super visory relays 72 and 74 are deonergized. The deenergization of relay 72 lights supervisory lamp 75, associated with the switch end of the link-circuit. by closing acircuit which may be traced from the live pole of the battery it, through the winding of relay S1, lamp 7:"), front contact 77 of'relay 71 and back contact 78 of relay 72 to ground. The closing of thisccircuit also energizes relay 81 to close a circuit througli pilot supervisory lamp S3 and front contact 85 of relay encrgization oi. relay 74 lights supervisory lamp 76 by closing a circuit which may be traced from the live pole of battery B, through lamp 76, front contact 79 of relay 73, and back contact 80 of relay 74 to ground. Upon observing the supervisory lamps lighted, the operator will take down the connection by removing plug P from jack This will at oncedecnergize sleeve supervisory relay 73 and extinguish lamp 76. It will also close a release circuit for the associated. switch M. This circuit, as before traced, extends from the battery, through the winding of relay 82, front con- 'act 93 of relay '71, back contact 92 of relay 73, back contact 91 of relay 72, conductor 67, switch contact -12. wiper 39, back contact 300i relay 18 and the winding of release magnet 53 to ground. The closing of this circuit will actuate said release magnet to cause the spring catch 50 on its armature 52 to engage the hooked projection 51 on rctaii'iing pawl 48 in readiness to withdraw said pawl upon dei nergixation of the release magnet to allow the switch to return to normal, under the tension of its return spring The engagement of catch 50 and projection 51 closes a circuit for magnet 20 from battery through the winding of said magnet, catch 50, projection 51 and pawl 48 to ground. As a result of the closing of this circuit, relay 20 opens the circuit of the extending line at contacts 31 and 32. The opening of the latter contact breaks the previous circuit over the sleeve side through 011 the other hand, the desleeve supervisory relay 71 and cut-0d relay 19. The return of the former extinguishes supervisory lamp 75 and pilot lamp 63. The return of the latter restores the line circuit to its normal condition. The return of the sleeve supervisory relay 71 also breaksthe release circuit through release magnet and thereby allows spring 54 and catch 50 to withdraw the retaining pawl'S and thus allow the switch parts to return to normal. Thus all the parts are brought to normal in .i'eadiness for the initiation of another call.

In order that the switch M may be kept in operation until a link-circuit N, having an idle operators set, is encountered, contacts 59 and 60 are arranged so as to release the switch when it overruns its operative contacts, in case it does not make connection with an idle operators set upon its first traverse, and thereby free it for a second, a third, or as manyas may be necessary before a connection is established. As before ex: plained, when the switch has stepped one step beyond the last operative contacts, projection (31 engages contact 59 and forces it into engagement with contact (30. This closes a release circuit for magnet 53 which may be traced from the live pole of battery B, through protective resistance 61, contacts 60, 59, back contact 34 of relay 20, and winding of release magnet {53 to ground. When restored as a result of this release operation, the switch is in readiness to begin another traverse because the line relay 18 is still energized. Similar traverses may follow.

It will, of course, be understood that the several ground connections in the diagram are connections to the return side of the battery. Likewise, where parts are common to a plurality of circuits, such as control. re- 70, pilot relays 81 and 82, and the operators sets, the common connections are indicated by a plurality of short lines radiating from the common connecting point. It will also be understood that when the lines L, L, are trunk lines, then their circuits must be such as to bring about-the operation of' 'the tip and sleeve supervisory relays 73 and 7- and the associated connec tions, just as explained where the lines T1 and L were assumed to be subscribers lines having line circuits similar to the line L. Many trunk circuits of the art are available for use with the particular form of linkcircuit illustrated. One such instance will be found illustrated in Fig. 290 on page 308 of :1 'mrzrimn, Telephone Practice, by Kempster R. Miller. Fourth Edition, and de scribed in the adjacent text. Other instances might be cited, but it is believed thisone will sullice.

As illustrative of relays having mechanical construction suitable for the operation of a plurality of contacts such as some of the relays in the present disclosure, attention is directed to the following United States atents issued'to E. E. Clement: 928,360, uly 20, 1909; 990,032, April 18, 1911 991,829, May 9, 1911. It Will also be understood that the link-circuits accessible to any one group of switches M may be variously distributed before operators having control of the plugs P according to expediency or the Will of the user. Likewise, the link-circuits of any one group may bedivided among any desired number of operates and the variousoperators sets may be made common toany desired individual link-circuits of the particular group.

It will also be apparent that other alterations and modifications may bemade in the particular embodiment of the invention herein disclosed Without departing from the spirit and scope of my invention and that my invention is capable of extended application. l, therefore, do not Wish to be limited to the particular embodiment herein disclosed, but aim to cover such alterations and modifications and the various applications thereof by the term of the appended claims.

WV hat I claim as new and desire to secure by Letters Patent of the United States is:-

1. A telephone system comprising circuits severally available for calling purposes, an operators telephone set common to said cir cuits, automatic switch mechanism for extending said circuits to said set, means under the control of an operator for further ex tending such extended circuits, and means' for indicating tea party calling over one of .said circuits when the operators receiver is in circuit ready for the operator to receive such partys order.

"2.; A telephone system comprising a circuit available for calling purposes, an operators telephone set for use With said circuit, other circuits for use With said set, automatic switchf mechanism for extending said first mentioned. circuit to said set, means under the control of an operator for further extending such extended circuit, and means for indicating to a party calling over said first mentioned circuit When the operators receiver is in circuit ready for the operator to receive such partys order. v

3. A telephone system comprising circuits severally available for calling purposes, operators telephone sets available for connec-. tion to said circuits, means responsive to calls over said circuits to connect said sets to di'fferent calling circuits, means for indicating to such calling parties when the operators sets are respectively in circuit ready for the operators to receive orders from such parties and means for freeing each said connecting means for .-.further service after the receipt of theoi der over the connections established by it.

4. A telephone system. comprising lines severally available for calling purposes, link v circuits available for connection to said lines,

an operators telephone set common to said llnK-cllclllts, means responsive to the 1n1t1ation of a call over any of said lines to connect 5. A telephone system comprising lines severally available for calling purposes, link-.

circuits available for connection to said lines, operators sets available for connection to said link-circuits, means responsive to the initiations of calls over said lines to connect the calling linesto idle ones of said link-cit cuits, means for indicating to the calling parties when the operators" sets are 1n c1rcult ready for the operators to receive such parties orders and means for freeing each said connecting means for further service after the receipt of the order over the connections established by it, 1 i

6. A telephone system comprising lines severally available for calling purposes,linkcircuits available for connection to said lines, an operators telephone set common to said link-circuits, means responsive to every ini tiation of a call over said lines to test said link-circuits successively in the same order and connect the calling line with an idle one of said link-circuits, means for indicating to the calling party when the cp'erator"s receiver is in circuit ready for the operator to receive such calling partys order, and means operative after t ereceipt of said order to, free said connecting means for fun 7 ther service.

7. A telephone system comprising lines severally available for calling purposes,

link-circuits available for connection to said. 7,

lines, operators set available for connection to said linkcircuits, means IQSPOHSlVQ to all initiations of calls over said linesto test said link-circuits successively in the same order and connect the calling lines to idle ones of said linlncircuits, means for indicating to the calling parties when the open" ators sets are in. circuit ready for the operators to receive such calling parties orders, and means for freeing each said connecting means for further service after the receipt of the order over the connections estair, lished by it.

8. A telephone system comprising circuits severally available for calling purposes, a telephone receiver 'operatively associated with the calling end of each oi said circuits,

means responsive to the initiation of a call over any of said circuits to vary the elecntly means responsive to the initiation of a call over any of said circuits to vary the elec trical coi'idition of said circuit to cause a characteristic sound in said receiver. iinhcircuits available for connectioi'i to said lines, an operators telephone set available for connection to said linh-circuits, means including automatic switch mechanism for connecting a (:allin c line to an idle one of said link-circuits. means for connecting said operatoNs-set to the same idle link-circuit, means for discontinuing the said sound, in said receiver at the time said set is thus connected, and means subsequently opera. tive to free said connecting means.

10. A telephone system comprising subscribers linesextending from substations to an exchange, subscribers telephone sets Operatively associated with said lines at the sul'istations, a line relay included in circuit With each said line upon initiation of a call thereover, means operated by said relay to vary the electrical condition of the assoch. vated circuit to cause a cl aracteristie sound in the calling partys receiver, link-circuits available for connection to said subscribers lines, an operatofis telephone set available for connection to said link-circuits, means for connecting a calling line to an idle one of said link-circuits, means torconnccting said operator-s set to the same idle link-circuit, and means for discontinuing the said sound in the callinp partys receiver at the time said operators set is thus connected.

11. A telephone system comprising subscribers lines extending from substations to an exchange, subscribers telephone sets operatively associated with said lines at the substations, line relay included in circuit with each said line upon initiation of a call. thereover, means operated by said relay to vary the electrical condition of the associated circuit to'cause a cluiracteristic sound in the c; lling partys receiver linlccircuits available for connection to said subscril'iers lines, an operators telephone set available for connection to said link-circuits, means for connecting; a calling line to an idle one of said llIlk-CllZCllltS, means for connecting said operatoi"s set to the said idle link-circuit, acut-ofl' relay for opening the circuit of said line relay to discontinue the said sound in the calling partys receiver, and

means for operating said cut-oi"l" at the time sa'd operators set is thus connected.

12. A telephone system comprising'circuits severally available for calling purposes, an operators telephone set common to said circuits, means responsive to the. initiation a call over any of said circuits to extend such circuit into conversational connection with the operators set but only when said set is free for use, and means under the control of an operator for further extending such an extended circuit.

33. A telephone system comprising a circuit available for calling; purposes, an operators telephone set for use with said circuit, other circuits for use with said set, means responsive to the initiation of a call over said first-mentioned circuit to extend it into conversational connection with said op, crators set but only when said set free for use, and n'ieans under the control of an operator for further extending such extended circuit.

ll. A telephone svsten'i comprising circuits severally available for calling purposes. operators telephone sets available for connection to said circuits, means responsive to calls over said circuits to extend said circuits individually into conversational conneclion with said sets but only when said set is Free for use, and means under the control of an operator for further extending such extended circuits.

15. It tele 'ihone system comprising lines severally available for calling purposes,

link-circuits available for connection to said lines, an operators telephone set cou'm'ion to said link-circuits, lllllIlS responsiveto the initiation of a call over any of said'lines to connect the calling line into conversational connection with one of said linlccircuits and thence to said operators set but only when the latter is free for use and means under operator control for further extending the conversational circuit thus established.

16. A telephone system comprising lines severally available for calling purposes, link- 'circuits available for connection to said lines,

operators sets available for connection to said link-circuits, u'ieans responsive to the initiations of :alls over said lines to certain of said linl-z-circuits and thence into conversational connection with said o 'ierators sets but only when the latter are tree for use and means underoi'ierator control for further extending the conversatioiuil circuits thus established.

17. A telephone system con'iprising lines severally available for calling purposes, linkcircuits available for connection to said lines, operators sets available for connection to said link-circuits, means responsive to the initiation of a. call over any of said lines to connect the. calling line to one of said linkcircuits and thence into conversational confurther extending the vconversational cirnection' with one of said operators sets but cuits thus established. only when the latter is free for use and means under operator control for further severally available for calling purposes, extending the conversational circuit thus eslink-circuits available for connection to said tablished. lines, operators sets available for connection 18. A telephone system comprising lines to said link-circuits, means responsive to 23.,A telephone system comprising lines severally available for calling purposes, linkevery initiation of a call over said lines to circuits available for connection to said lines, test said link circuits successively in the an operators telephone set common to said same order and connect the calling line and link-circuits, means responsive to the initian idle one of said link-circuits into a conation of a call over any of said lines to conversational circuit with the operators set 'nect the calling, line and an idle one of said associated with that link-circuit and means link-circuits into a conversational circuit under operatorcontrol forfurther extend with the operators set and means under op erator control for further extending the conversational circuit thus established. 24. A telephone system comprising cir- .19. A telephone system comprising lines cuits severally available for calling purseverally available for calling purposes, linkposes, an operators telephone set common to circuits available for connection to said lines, said circuits, means responsive to the initiaoperators sets available for connection to tion of a call over any of said circuits to said link-circuits, means responsive to the extendsuch circuit into conversational coninitiations of calls over said lines to connect nection with the operators set but only When the calling lines and idle ones of said linksaid set isfree for use, means operative upon circuits into conversational circuits with the the establishment of such extension to inassociated operators sets and means under dicate to the calling party that the operator operator control for further extending the is free and ready. to receive such calling conversational circuits thus established.

partys order, and means underthe control 20. A telephone system comprising lines of an operator for further extending such severally available for calling purposes, linkan extended circuit.

circuits available forconnection to said lines, 25. Atelephone system comprising a cir operators sets, available for connection to cuit available for calling purposes, an opsaid linkcircuits, means responsive to the erators telephone set for use with said cirinitiation of a call over any of said lines to cuit, other circuits for use with said set, connect the calling line and an idle one of means responsive to the initiation of acall said liiilccircuits into a conversational cirover said first mentionedcircuit to extend cuit with the operators set associated with it into conversational connection with said that link-circuit 'and'means under operator operators set but only when said set is free control for further extending the conversa for use, means operative-upon the establishtional circuit thus established. ment of, such extension to indicate to the 21. A telephone system comprising lines calling party that the operator is free and severally available forcalling purposes, linkready to receive such'calling partys order, circuits available for connection to said lines, and means under the control of an operator an operators telephone set common to said for further extending such extended cirlink-circuits, means responsive to every'inicuit.

tiation of a call over said lines to test said 26. A telephone system comprising cirlink-circuits successively in the same order cuits severally available for calling purand connect the calling line and an idle one poses, operators telephone sets available for of said link-circuits into a' conversational connection to said circuits, means responsive circuit with said operators set and means to calls over said circuits to connect. said under operator control for further cxtendcircuits individually to said sets When free ing the conversational circuit thus estabfor use, means operative upon the establishlished. ment of such connections to indicate ,to the 22. A telephone system comprising li calling parties thattheir respective operaseverally available for calling purposes, tors are ready to receive such calling parlink-circuits availablefor connection to said ties orders, and means for freeing each said P u 0rS sets available for conneC- connecting means for further service after tion to said linlccircuits, means responsive the receipt of the order over the connecto all initiations of calls-over said lines to tions established by it. V test said link-circuits successively in the 27. A telephone system comprising lines same order and connect the calling lines and severally available for calling purposes, idle ones of said link-circuits into conversalink-circuits available for connection to said tional circuits with the associated operators circuits, an operators telephone set common sets and means under operator control for to said link-circuits, a relay common to said link-circuits, ltutonmtic means for connecttors sets available for use with circuits available ing a calling line to idle one of said linkcircuits Whenever ssicl relay is deenergized, means iOl cleinergizing said relay only when said operators set is free for use and means for automatically connecting said operators set intoconversotional connection with the uti zod link circuit. 7

A telephone system comprising lines severally svailuble for calling purposes, link-circuits available for connection to said lines, other lines severally available as called lines; an operator-"s telephone set common to said link-circuits, means under the opera tors control for connecting said linlecir cults to said other lines, a relay common to said link-*ircuits automatic means operative in response to a] call over any of said first mentioned lines to connect such line to an idle link-circuit whenever said relay is deeper-glued, moons responsive to the con nection of it selected. link-circuit to it called line to deenergize said relay, and means for automatically connecting said operators set into conversational connection with the utilized link circuit 29. A telephone system comprising circuits severally available for calling purposes, operators telephone sets available for connection to said circuits, means responsive to the initiation of a call over any of said circuits to test said operators sets successively a." connect said calling circuit into converconnection with the first said set found idle and means under operator control for further extenoiug the conversational circuit thus established.

30 A telephone system comprising a circuit available "for calling purposes, operasaid circuit and otherwise, means responsive to the initiation a call over said circuit to test said operators sets successively and connect said calling circuit into conversational connection. with the first said set found idle and means under operator control for further eXtending the conversational circuit thus established.

A telephone system comprising cir cuits severally available for calling purposes,

operators telephone sets available for connection to said circuits, means responsive to the initicti ns of calls over said circuits to test said perctors sets successively and connect said calling circuits individually into conversational connection with the first said set found idle and means under operator conrol for further extending the conversational circuit thus established.

f ohone system comprising lines sever y available for calling purposes, linkfor connection to said lines, operators sets available for connection each to of said i i-circuits, means respcnsivc the lnl'bi no.1 of a call over any to the initiation of a call of said lines totest the link-circuits of the different operators sets successively and connect such calling line through a link-circuit into conversational circuit with the first operators set found idle and. means under operator control for further extending the conversational circuitthus established.

A telephone system comprising lines severally available for calling purposes, linlo circuits available for connection to said lines,

} operators sets available for connection each to a plurality of said link-circuits, means responsive to the initiations of calls over said lines to test the link-circuits of the different operators sets successively and connect such calling lines respectively through link-circircuit with the first operators set found idle and means under operator control for further extending the conversational circuit thus established.

35. A telephone system comprising lines severally available for calling purposes, linkcircuits available for connection to said lines,

.operators sets available for connection each to a plurality of said link-circuits, means responsive to all initiations of calls over said lines to test the link-circuits oi the different operators sets successively in the same order and connect the calling lines respectively through link-circuits into conversational cir cuits With the first operators sets found idle' and means under operator control for further extending the conversational circuits thus established.

36. A telephone system comprising circults severally available for calling operators telephone sets available for connection to said circuits means responsive over any of said circuits to test said operators sets successively and connect said calling circuit to the first said set found idle, means for indicating to the calling party When the operators receiver is in circuit ready for the operator to receive such calling partys order and means operative after the receipt of said order to free said connecting means for further service.

purposes, 1

' conversational circuit with the operators set nection to said circuits, means responsive to the initiation of a call over any of said lines to automatically bring one of said o erators sets into connection with said calling 'circuit, means for indicating to the calling party when the receiver of operator, whose set is thus connected, is connected in circuit and ready for-the operator to receive such calling partys order and means operative after the receipt of said order to free said connecting means for further service. a

38. A telephone system comprising circuits severally available for calling purposes,.operators telephone sets available for connection to said circuits, a relay individual to each operators set,'means for maintaining said relays energized or deenerglzed according to the busy or idle conditions of the associated operators sets respectively, means responsive to the initiation of a call over any of said circuits to test the conditions of said relays and to connect said calling line into conversational circuit with the operators set whose relay is first found idle and means under operator control for further extending the conversational circuit thus established.

39. A telephone system comprising lines severally available for calling purposes, link-circuits available for connection to said lines, operators telephone sets available for connection to said link-circuits, a relay for each operators set, means for maintaining said relays energized or deenergized according to the busy or idle condition of the .associated operators. sets respectively, means responsive to the initiation of a call over any of said circuits to test the conditions of said relays and to connect said calling line to a link-circuit and thence into conversational circuit with'that operators set Whoserelay is first .found idle and means under operator control for further extending the conversational circuit thus established.

40. A' telephone system comprising lines severally available for calling purposes,-

link-circuits available for connection to said lines, switch mechanism for connecting said lines and link-circuits, said mechanism ineluding test contacts, telephone sets available for connection to said link-circuits, relays individual to said operators sets and operative to determine the busy or idle condition of said test contacts according to the busy or idle condition of the respective operators sets, means responsive to the initiation of a call over any of said lines to operate said switch mechanism to connect the calling hnc to a link-circuit'and thence into whose relay is first found idle and means under operator control for further extending the conversational circuit thus estal,

connection to said link-circuits, relays inresponse to the connections of calling lines to link-circuits associated with them, means for deenergizing said relays in response to the connections of selected associated linkcircuits to said other lines as called lines and means under operator control for further extending, the conversational circuits thus established.

42'. A telephone system comprising cir- I I cuits severally available for calling purposes, an operators telephone set common to said circuits, automatic switch mechanism for extending said circuits into conversational connection with said set, means under the control of an operator for further extend ing such extended circuits, and means for preventing said mechanism from extending a calling circuit until the orders of all previous calls have been received by an operator.

43. A telephone system comprising circuits severally available for calling purposes, operators telephone sets available for con-' nection to 'said circuits, automatic switch mechanism for extending said circuits into conversational connection with said sets, means under operator control for further extending such extended circuits, and means for preventing said mechanism from extending a calling circuit to any particular'op erators set until the orders of all previous calls for that operator have been received by her.

44. A telephone system comprising circuits severally available for calling purposes, an 'operators telephone set common to said circuits, automatic switch mechanism responsive to calls over said circuits to extend said circuits into conversational connection with said set, said mechanism refusing to thus extend more than one circuit so long as said set is in use, and means under operator control for further extending such extended circuits.

45. A telephone system comprising circuits severally available for calling purposes, operators telephone sets available for connection to said-circuits. automatic switch. mechanism responsive to calls over said circuits to extend said circuits into conversational connection with said sets, said mecha nism refusing to extend more than on epin cuit .per set so long as said set is infuse,

and means under operator control for further extending such extended circuits.

46. A telephone system comprising lines severally available for calling purposes,

link-circuits available for connection to said .lrnes, an operators telephone set common to said link-circuits, means responsive to calls over said lines to connect said set to said link-circuits and thence to the calling lines, the set being connected to but one link-circuit and line at a time and means under operator control for further extend ing the circuit thus established by said connecting means.

47. A telephone systemcomprising lines severally available for calling purposes, link-circuits available for connection to said lines, operators telephone sets available for connection to said link-circuits, means responsive to calls over said lines to connect said sets to different link-circuits and thence to different calling lines, each set being connected to but one link-circuit and line ata time and means under operator control for further extending the circuit thus established by said connecting means. i

48. A telephone system comprising cir cuits severally available for calling purposes, an operators telephone set common to said circuits, means for automatically restricting the operatorsattention to-one call at a time, means for indicating tothe calling party when the operators receiver is in circuit ready for the operator to receive such calling partys order and means operative after the receipt of said order to tree said restricting means for further service.

49. A telephone system comprising circuits severally available for calling purposes, operators sets available for connection to said circuits. means responsive to the initiations of calls over said circuits to automatically bring said operators sets into several connection with said calling circuits, means for indicating to the calling parties when the operators sets are in circuit ready for the operators to receive the calling parties orders and means for freeing each said connecting means for further service atter the receipt of the order over the connections established by it.

50. A telephone system comprising circuits severally available for calling purposes. an operators telephone set common to said circuits. means responsive to the initiation of a call over any of said circuits to connect such circuit into conversational circuit with said operators set when idle, means "for preventing other calling circuits from being connected therewith until the operator has performed a subsequent act and means under operator control for further extepding; the conversational circuit thus a calling one of said circuits into conver tablished.

messes 51. A telephone system coml'irising circuits severally available for calling purposes, an operators telephone set common to said circuits, means responsive to the initiation or a call over any of said circuits to connect such circuit-into conversational circuit'with said operators set when idle, a relay for determining the selectivity of said operators set, means under the control of the operator for actuating said relay and means under operator control for further extending the conversational circuit thus es tablished. I

A telephone system comprising circuits severally available for calling purposes, an operators set common-to said circuits, a control relay. means responsive. to the initiation of a call over any of said circuits to connect said circuit into conversat-ional circuit with said operators'set upon one condition of said relay and to pass by said set upon another condition of said re lay, relays and circuits under the control of the calling part 7 and the operator for establishing the different conditions of said relay and means under operator control for further extending any conversational circuit thus established. v i

A telephone system comprising lines severally available. for calling purposes,. link-circuits available for connection to said lines, an operators set common to said linkcircuits, switch mechanism for connecting said lines and link-circuits, relays and circuits for connecting said operators set to said link-circuits, a control relay for determining the. action of said switch mecha-' nism and said relays and circuits, and means under the control of the operator for determining the action of said control relay.

5%. A telephone system comprising lines severally available for calling purposes, link-circuits available for connection to said lines, other lines aailable as calledlines, an operators set available for connection to said link-circuits, switch mechanism for connecting said lines and link-circuits, relays and circuits for connecting said operators set to said link-circuits. a control relay for determining the action of saiclswitch mechanism and said relays and circuits accordinn to its energized or deelnergized condition, means responsive to the connection of said lines and link-circuits to energize said control relay, and means responsive to the connection of said link-circuits to said other lines to deenergize said control relay.

A' telephone system comprising circuits severally available for calling purposes, an operators telephone set available .tor connection to said circuits. automatic .idle condition of said operators telephone set for extending said first-mentioned circuit into conversational connection with said set, and means under operator control for further extending such extended circuit.

57.. A telephone system, comprising circuits severally available for calling purposes,

operators telephone sets available for connection to said circuits, automatic means dependent upon the idle condition of said operators sets to extend calling ones of said circuits into conversational connection with said sets'severally, and means under operator control for further extending such extended'cir'cuits. v I

58. A telephone system comprising lines severally available for calling purposes, link-circuits available for connection to sald lines, an operators telephone set available for connection to said link-circuits, and means dependent upon the idle condition of said operators set for connecting it to one of said link-circuits and thence automatically to a calling one of said lines.

59. A telephone system comprising a line available for calling purposes, link-circuits available for connection to said line, an operators telephone set available for use with said link-circuits and otherwise, and means dependent upon the idle condition of said operators telephone set for connecting it to one of said link-circuits and thence automatically to said line in response to a call over said line.

60. Ina telephone system comprising lines severally available for calling purposes, link-circuits available for connection to said lines, operators telephone sets available for connection to said link-circuits, and means dependent upon the idle condition of said operators sets to connect said sets to different link-circuits and thence automatically to different calling lines.

61. A telephone system comprising circuits severally available for calling purposes, an operators telephone set available for connection to said circuits, means. dependent upon the-idle condition of said'operators set' for connecting it to a calling one of saidcircuits, means for indicating to the calling party when the operators .receiver is in circuit ready for the operator to receive his order and means under operator control for further extending the conversational circuits thus established. 4

62. A telephone system comprising circuits severally available for calling purposes, operators telephone sets available for connection to said circuits, means dependent upon the idle condition of said operators telephone sets to connect them severally to calling ones of said circuits, means for severally indicating to the calling parties when the operators sets are in circuit ready for the operators to receive their orders and means for freeing each said connecting means for further service after the receipt gt the orderover the connections established y it.

63. A telephone system comprising circuits severally available for calling purposes, an operators'telephone set available for connection to said circuits, a control relay, means for giving it a definite electrical condition When said operators set is not in use, means for automatically connecting a calling one of said circuits into conversational connection with said operators set While said control relay is in said electrical condition and means under operator control for further extending the conversational circuits thus established.

64:. A telephone system comprising circuits severally available for calling purposes, an operatons set available for connection to said circuits a control relay beingener gized or deenergized according to the busy or idle condition of said operators set, travcling means responsive to the initiation of a call over any of said circuits to pass or es tablish a conversational circuit with said operators set accordin to the energized or denergized condition of said control relay and means under operator control for furcorresponding to the busy and idle conditions of said operators set, automatic switch mechanism for connecting said lines and link-circuits into conversationalcircuits With said operators set, means for determining the operation of said mechanism according to the condition of said control relay and means under operator control for further extending the conversational circuits thus established.

66. A telephone system. comprising lines severally available for calling purposes, link-circuits available for connection to said lines an operators telephone set available for connection to said link-circuits, automatic switch mechanism for connecting said lines andlink-oircuits into conversational circuits with said 'operators set, other lines available for connection as called lines, means under the operators control for bringing about such latter connections and extending the conversational circuits thus established to include said called lines, a control relay, means for closing a circuit for said relay upon the connection of a callcuits severally available for calling purposes, other circuits severally available for called purposes, means, including automatic switch mechanism, for uniting calling and called circuits, part of said means being under the control of an operator, an operators telephone set adapted for inclusion in a conversational circuit with a party calling over one of said calling circuits, and means for indicating to such a calling party when the operatofis receiver is in circuit ready for the opera? r to receive such partys order.

(38. system comprising circuits severally avail le for calling; purposes, calling mechanisn associated with each of said circuits requiring a plurality of actson the partof the calling party to make a call, receiving mechanism common to said circuits, automatic switch mechanism for extending said circuits to said receiving, mechanism, means under operator control for turtlier extending such extended'circuits, and means responsive to the initiation of a call over any of said circuits to indicate when said receiving mechanism is in condition for the subsequent act, or acts, of the calling party.

69. A telephone system comprising circuits severally available for calling purposes,

other circuits severally a ailable for called purposes, an operators telephoneset common to said first mentioned circuits, automatic sw tch mechanism responsive to the 111- itiation or" a call over any-of said circuits to.

extend such circuit into conversational connection with the operatofis set, but only when said set is free for use,-and means under the control of an operator for combining with said switch mechanism to-unitc calling and called circuits. I

70. A telephone system comprising circuits severally available for calling purposes,

other circuits severally available for called purposes, an operators telephone set com mon to said first mentioned circuits, automatic switch mechanism responsive to the initiation of a call over any of said circuits to extend such circuit into conversational connection with the operators set, but only when saidset is free for use, means opera tive upon the establishment of such extenmasses 'sion to indicate to the calling party that the operator is free to receive the calling partys order, and means under the control. of an operator for combining with said switch mechanism to unite calling and called circuits.

' 71. A system comprisingcircuits severally available for calling purposes, calling mech anism associated with the calling end of each said circuit, requiring a plurality of acts on the part of the calling party to make a call, receiving mechanism common to said circuits, means '-responsive to the initiation or" a call over any of said circuits to'connect such calling circuit with said receiving mechanism when the latter is free for use, means for indicating to the calling party that said receiving mecl'ianism is in condition for such partys further calling act, or acts and means operative after the performance of said act, or acts, to free said connecting means for further service,

72. A telephone s, stem comprising circuits severally available for calling purposes, other circuits severally available for called purposes, means, including automatic switch mechanism, fortunitingcalling and called circuits, part of said means being under the control of operator, means cooperating with said uniting means to en able orders of calling parties to be communicated to an operator, anc means for preventing the communication of any such calling partys order until all the orders of previously calling parties have received by the operat r and the operators receiver is in ci cult ready for the operator to receive such order.

73. A telephone system comprising circuits severally available 'it'cr calling purposes, other circuits available for called purposes, incluc 11g automatic switch mechanism, for uniting calling and called circuits, part said means being under the control of an operator, and means cooperating with said uniting means in response to calls over said circuits to enable orders of calling parties to be communicated to an operator and to prevent the communication of any such cal ing partys order so long as the orders of previously calling parties have not been received by the'oporator and the operators receiver is in circuit ready for the operator to receive such order.

74. A system comprising circuits severi lly available for calling purposes, callingmechanism associated with the calling end oi each said circuit, requiring a plurality of acts on the partof the calling party to make a call,

receiving mechanisms available for connec' tion to said circuits, means responsive to the initiation ofa, call over any of said circuits to test said receiving mechanisms succescircuits sively and connect such calling line to the first such receiving mechanism found idle, means for indicating to the callingparty that the said receiving mechanism thus connected is in condition for such partys further calling act, or acts and means operative after the performance of said act, or acts, in

erators telephone set, and means cooperating with said uniting means to extend a calling one of said circuits into conversational connection with said set, said combined means being dependent in' their extending function upon the idle condition of said operators telephone set.

76. A system comprising circuits severally available for calling purposes, calling mechanism associated With the calling end of each said circuit, requiring a plurality of acts on the part of the calling party to make a call, a receiving mechanism common to said circuits, means for automatically .connecting, and rest-'cting'the'connection of, said receiving mechanism to one of said it a time, for indicating to the calling party \v rid receiving mechanism in condiin for such partys further calling act, or acts, and means operative after the performance of said act, or acts, to free said connecting means for. further service.

77. A system comprising lines severally available for calling purposes, conductors available for interchangeable connection to said lines, receiving mechanism available for connection to said conductors, and means dependent upon the idle condition of said receiving mechanism for connecting it to one of said conductors and thence automatically to a calling one of said lines.

78. A system comprising circuits severally available for calling purposes, calling mechanism associated with the calling end of each said circuit, requiring a plurality of ,acts on the part of the calling party to make a call, a receiving mechanism available for connection to said circuits, means dependent upon the idle condition of said receiving mechanism for connecting said mechanism to a calling one of said circuits, means for indicating to the calling party when said automatic receiving mechanism is in condition for such.

partys further calling act, or acts and means operative after the performance of said act, or acts, to free said connecting said circuits, means for connecting a calling.

circuit to said receiving telephone,;means for discontmmng the operationofsaid receiver as soon as and only as-soon as said receiving telephone is thus connected and means subsequently operative connecting means,

80. A system comprising lines severally available for calling purposes, a receiver associated with the calling end of each of said circuits, a line relay included in circuit with each said line upon initiation of a call thereover, means operated directly by saidrelay to continuously operate said receiver,"conductors available for interchangeable connectlon to said lines, a receivlng telephone available for connection to said conductors",- means for connecting a calling line to an to free said.

idle conductor, means for connecting said receiving telephone to the same conductor, and means for discontinuing theoperation 'of said receiver as soon as said receiving mechanism. is thus connected. c

81. A system comprising lines severally urposes' a recelveravailable for calling associated with the cal ing en of each of saidcircuits, a line relay included in circuit with each said line upon initiation of a call thereover, means operated by said relay to continuously operate said receiver, conductors available for connection tosaid lines, receiving mechanism available for connection to said conductors, means for connecting a calling llne'to an idle .con-

ductor, means for connectin; said receiving.

mechanism to the same conductor, a cut-off.

relay for opening the circuit of said linerelay to discontinue the operation of said receiver by reason of the means controlled by said latter relay, and means for operating said cut-oil relay as soon as said receiving mechanism is thus connected.

In witness whereof, I hereunto subscribe my name this 5th day of November, 1912.

LE nor W. STANTON.

Witnesses T, H. Fnncnson, J. W. BENNETT.

ion's i Comet is heieby ceitifieci that in Letters Patent No. 1,156,253, greeted Octoher '12,

1915, upon the application of Le Roy W. Stanton, of Cleveland, Ohio, for an im PTOYGHZGIN in Telephone Systems, oi-roi's appear in the printed specification i'equiring correction as follows: Page 1, line 93, for the Won substehtion read substation; page 4, line 120, before the WON. isl. insert the WOId it; page 7, line 110, claim 7, forthe Word set read sets; page 8, line 50, claim 11, hefore the Word lino insert the article a; page 13, line 63, claim 61; liiies 8990, claim 63,

and line 103, claim (34, for the Word circuits read circ t'lt; and that the said Letters Potent should be read with these corrections therein that the same may conform to the record of the case in thePatent Ofiioc. I

Signed and sealed this 2nd day of November, A. D., 1915.

[SEAL] R. F. WHI'lEHEAD,

Acting Commissz'o'fiec of Patents. 

